sstable: set minlz compression to default for v6+

set minlz to default compression for v6+, have a guard against
using minlz for v5 and earlier.

Author: EdwardX29

metamorphic/options.go

@@ -786,14 +786,16 @@ func RandomOptions(
 		lopts.FilterPolicy = newTestingFilterPolicy(1 << rng.IntN(5))
 	}
 
-	// We use either no compression, snappy compression or zstd compression.
-	switch rng.IntN(3) {
+	// We use either no compression, snappy compression, zstd compression, or minlz compression.
+	switch rng.IntN(4) {
 	case 0:
 		lopts.Compression = func() block.Compression { return pebble.NoCompression }
 	case 1:
 		lopts.Compression = func() block.Compression { return pebble.ZstdCompression }
-	default:
+	case 2:
 		lopts.Compression = func() block.Compression { return pebble.SnappyCompression }
+	default:
+		lopts.Compression = func() block.Compression { return pebble.MinlzCompression }
 	}
 	opts.Levels = []pebble.LevelOptions{lopts}
 

options.go

@@ -2160,7 +2160,7 @@ func (o *Options) MakeBlobWriterOptions(level int) blob.FileWriterOptions {
 
 func resolveDefaultCompression(c Compression) Compression {
 	if c <= DefaultCompression || c >= block.NCompression {
-		c = SnappyCompression
+		c = MinlzCompression
 	}
 	return c
 }

replay/testdata/replay

@@ -11,7 +11,7 @@ tree
      614      000007.sst
        0      LOCK
      133      MANIFEST-000001
-    1524      OPTIONS-000003
+    1523      OPTIONS-000003
        0      marker.format-version.000001.013
        0      marker.manifest.000001.MANIFEST-000001
             simple/
@@ -21,7 +21,7 @@ tree
       25        000004.log
      586        000005.sst
       85        MANIFEST-000001
-    1524        OPTIONS-000003
+    1523        OPTIONS-000003
        0        marker.format-version.000001.013
        0        marker.manifest.000001.MANIFEST-000001
 
@@ -79,7 +79,7 @@ cat build/OPTIONS-000003
   block_restart_interval=16
   block_size=4096
   block_size_threshold=90
-  compression=Snappy
+  compression=Minlz
   filter_policy=none
   filter_type=table
   index_block_size=4096

replay/testdata/replay_paced

@@ -14,7 +14,7 @@ tree
        0      LOCK
      133      MANIFEST-000001
      205      MANIFEST-000010
-    1524      OPTIONS-000003
+    1523      OPTIONS-000003
        0      marker.format-version.000001.013
        0      marker.manifest.000002.MANIFEST-000010
             high_read_amp/
@@ -26,7 +26,7 @@ tree
       39        000008.log
      560        000009.sst
      157        MANIFEST-000010
-    1524        OPTIONS-000003
+    1523        OPTIONS-000003
        0        marker.format-version.000001.013
        0        marker.manifest.000001.MANIFEST-000010
 

sstable/options.go

@@ -331,6 +331,9 @@ func (o WriterOptions) ensureDefaults() WriterOptions {
 		o.Comparer = base.DefaultComparer
 	}
 	if o.Compression <= block.DefaultCompression || o.Compression >= block.NCompression {
+		o.Compression = block.MinlzCompression
+	}
+	if o.Compression == block.MinlzCompression && o.TableFormat <= TableFormatPebblev5 {
 		o.Compression = block.SnappyCompression
 	}
 	if o.IndexBlockSize <= 0 {

sstable/testdata/copy_span

@@ -173,7 +173,7 @@ d#0,SET: foobar
 
 copy-span test3 test4 b.SET.10 cc.SET.0
 ----
-copied 928 bytes
+copied 921 bytes
 
 iter test4
 ----
@@ -183,7 +183,7 @@ d#0,SET: foobar
 
 copy-span test3 test5 a.SET.10 bb.SET.0
 ----
-copied 936 bytes
+copied 918 bytes
 
 iter test5
 ----
@@ -213,7 +213,7 @@ d#0,SET: foobar
 
 copy-span test32 test33 b.SET.10 cc.SET.0
 ----
-copied 928 bytes
+copied 921 bytes
 
 iter test33
 ----
@@ -223,7 +223,7 @@ d#0,SET: foobar
 
 copy-span test32 test34 a.SET.10 bb.SET.0
 ----
-copied 936 bytes
+copied 918 bytes
 
 iter test34
 ----

sstable/testdata/rewriter_v6

@@ -45,9 +45,9 @@ sstable
  ├── index  offset: 363  length: 37
  ├── top-index  offset: 405  length: 52
  ├── fullfilter.rocksdb.BuiltinBloomFilter  offset: 462  length: 69
- ├── properties  offset: 536  length: 572
- ├── meta-index  offset: 1113  length: 88
- └── footer  offset: 1206  length: 57
+ ├── properties  offset: 536  length: 583
+ ├── meta-index  offset: 1124  length: 88
+ └── footer  offset: 1217  length: 57
 
 scan
 ----
@@ -80,9 +80,9 @@ sstable
  ├── index  offset: 367  length: 37
  ├── top-index  offset: 409  length: 56
  ├── fullfilter.rocksdb.BuiltinBloomFilter  offset: 470  length: 69
- ├── properties  offset: 544  length: 572
- ├── meta-index  offset: 1121  length: 88
- └── footer  offset: 1214  length: 57
+ ├── properties  offset: 544  length: 583
+ ├── meta-index  offset: 1132  length: 88
+ └── footer  offset: 1225  length: 57
 
 scan
 ----
@@ -115,9 +115,9 @@ sstable
  ├── index  offset: 367  length: 37
  ├── top-index  offset: 409  length: 56
  ├── fullfilter.rocksdb.BuiltinBloomFilter  offset: 470  length: 69
- ├── properties  offset: 544  length: 572
- ├── meta-index  offset: 1121  length: 88
- └── footer  offset: 1214  length: 57
+ ├── properties  offset: 544  length: 583
+ ├── meta-index  offset: 1132  length: 88
+ └── footer  offset: 1225  length: 57
 
 scan
 ----
@@ -150,9 +150,9 @@ sstable
  ├── index  offset: 367  length: 37
  ├── top-index  offset: 409  length: 56
  ├── fullfilter.rocksdb.BuiltinBloomFilter  offset: 470  length: 69
- ├── properties  offset: 544  length: 572
- ├── meta-index  offset: 1121  length: 88
- └── footer  offset: 1214  length: 57
+ ├── properties  offset: 544  length: 583
+ ├── meta-index  offset: 1132  length: 88
+ └── footer  offset: 1225  length: 57
 
 scan
 ----
@@ -186,9 +186,9 @@ sstable
  ├── index  offset: 363  length: 37
  ├── top-index  offset: 405  length: 52
  ├── fullfilter.rocksdb.BuiltinBloomFilter  offset: 462  length: 69
- ├── properties  offset: 536  length: 572
- ├── meta-index  offset: 1113  length: 88
- └── footer  offset: 1206  length: 57
+ ├── properties  offset: 536  length: 583
+ ├── meta-index  offset: 1124  length: 88
+ └── footer  offset: 1217  length: 57
 
 scan
 ----

sstable/testdata/writer_blob_value_handles

@@ -111,37 +111,37 @@ sstable
  │    ├── 00000    block:0/154
  │    │   
  │    └── trailer [compression=none checksum=0xda1c8436]
- ├── properties  offset: 200  length: 562
+ ├── properties  offset: 200  length: 559
  │    ├── 00000    obsolete-key (13)
  │    ├── 00013    pebble.colblk.schema (65)
  │    ├── 00078    pebble.num.values.in.blob-files (32)
  │    ├── 00110    pebble.raw.point-tombstone.key.size (36)
  │    ├── 00146    rocksdb.block.based.table.index.type (40)
  │    ├── 00186    rocksdb.comparator (42)
- │    ├── 00228    rocksdb.compression (25)
- │    ├── 00253    rocksdb.compression_options (122)
- │    ├── 00375    rocksdb.data.size (19)
- │    ├── 00394    rocksdb.deleted.keys (21)
- │    ├── 00415    rocksdb.filter.size (20)
- │    ├── 00435    rocksdb.index.size (19)
- │    ├── 00454    rocksdb.merge.operands (23)
- │    ├── 00477    rocksdb.merge.operator (40)
- │    ├── 00517    rocksdb.num.data.blocks (24)
- │    ├── 00541    rocksdb.num.entries (20)
- │    ├── 00561    rocksdb.num.range-deletions (28)
- │    ├── 00589    rocksdb.property.collectors (41)
- │    ├── 00630    rocksdb.raw.key.size (21)
- │    ├── 00651    rocksdb.raw.value.size (24)
- │    └── trailer [compression=snappy checksum=0xf0c5768d]
- ├── meta-index  offset: 767  length: 46
- │    ├── 0000    rocksdb.properties block:200/562
+ │    ├── 00228    rocksdb.compression (24)
+ │    ├── 00252    rocksdb.compression_options (122)
+ │    ├── 00374    rocksdb.data.size (19)
+ │    ├── 00393    rocksdb.deleted.keys (21)
+ │    ├── 00414    rocksdb.filter.size (20)
+ │    ├── 00434    rocksdb.index.size (19)
+ │    ├── 00453    rocksdb.merge.operands (23)
+ │    ├── 00476    rocksdb.merge.operator (40)
+ │    ├── 00516    rocksdb.num.data.blocks (24)
+ │    ├── 00540    rocksdb.num.entries (20)
+ │    ├── 00560    rocksdb.num.range-deletions (28)
+ │    ├── 00588    rocksdb.property.collectors (41)
+ │    ├── 00629    rocksdb.raw.key.size (21)
+ │    ├── 00650    rocksdb.raw.value.size (24)
+ │    └── trailer [compression=minlz checksum=0xefe5c665]
+ ├── meta-index  offset: 764  length: 46
+ │    ├── 0000    rocksdb.properties block:200/559
  │    │   
- │    └── trailer [compression=none checksum=0xaa86f2de]
- └── footer  offset: 818  length: 57
+ │    └── trailer [compression=none checksum=0x3da86560]
+ └── footer  offset: 815  length: 57
       ├── 000  checksum type: crc32c
-      ├── 001  meta: offset=767, length=46
+      ├── 001  meta: offset=764, length=46
       ├── 004  index: offset=159, length=36
-      ├── 041  footer checksum: 0xe7d8ef2e
+      ├── 041  footer checksum: 0x35ccc1c0
       ├── 045  version: 6
       └── 049  magic number: 0xf09faab3f09faab3
 

sstable/testdata/writer_v6

@@ -96,7 +96,7 @@ rocksdb.raw.value.size: 0
 rocksdb.deleted.keys: 9
 rocksdb.num.range-deletions: 9
 rocksdb.num.data.blocks: 0
-rocksdb.compression: Snappy
+rocksdb.compression: Minlz
 rocksdb.compression_options: window_bits=-14; level=32767; strategy=0; max_dict_bytes=0; zstd_max_train_bytes=0; enabled=0; 
 rocksdb.comparator: pebble.internal.testkeys
 rocksdb.data.size: 0
@@ -228,32 +228,32 @@ seqnums:  [1-1]
 layout
 ----
 sstable
- ├── data  offset: 0  length: 74
- ├── data  offset: 79  length: 74
- ├── data  offset: 158  length: 74
- ├── index  offset: 237  length: 36
- ├── index  offset: 278  length: 37
- ├── index  offset: 320  length: 37
- ├── top-index  offset: 362  length: 48
- ├── properties  offset: 415  length: 554
- ├── meta-index  offset: 974  length: 46
- └── footer  offset: 1025  length: 57
+ ├── data  offset: 0  length: 72
+ ├── data  offset: 77  length: 72
+ ├── data  offset: 154  length: 72
+ ├── index  offset: 231  length: 36
+ ├── index  offset: 272  length: 37
+ ├── index  offset: 314  length: 37
+ ├── top-index  offset: 356  length: 48
+ ├── properties  offset: 409  length: 530
+ ├── meta-index  offset: 944  length: 46
+ └── footer  offset: 995  length: 57
 
 # Exercise the non-Reader layout-decoding codepath.
 
 decode-layout
 ----
 sstable
- ├── data  offset: 0  length: 74
- ├── data  offset: 79  length: 74
- ├── data  offset: 158  length: 74
- ├── index  offset: 237  length: 36
- ├── index  offset: 278  length: 37
- ├── index  offset: 320  length: 37
- ├── top-index  offset: 362  length: 48
- ├── properties  offset: 415  length: 554
- ├── meta-index  offset: 974  length: 46
- └── footer  offset: 1025  length: 57
+ ├── data  offset: 0  length: 72
+ ├── data  offset: 77  length: 72
+ ├── data  offset: 154  length: 72
+ ├── index  offset: 231  length: 36
+ ├── index  offset: 272  length: 37
+ ├── index  offset: 314  length: 37
+ ├── top-index  offset: 356  length: 48
+ ├── properties  offset: 409  length: 530
+ ├── meta-index  offset: 944  length: 46
+ └── footer  offset: 995  length: 57
 
 scan
 ----
@@ -298,9 +298,9 @@ layout
 sstable
  ├── index  offset: 0  length: 28
  ├── range-key  offset: 33  length: 84
- ├── properties  offset: 122  length: 577
- ├── meta-index  offset: 704  length: 65
- └── footer  offset: 774  length: 57
+ ├── properties  offset: 122  length: 574
+ ├── meta-index  offset: 701  length: 65
+ └── footer  offset: 771  length: 57
 
 props
 ----
@@ -312,7 +312,7 @@ rocksdb.num.range-deletions: 0
 pebble.num.range-key-dels: 0
 pebble.num.range-key-sets: 3
 rocksdb.num.data.blocks: 0
-rocksdb.compression: Snappy
+rocksdb.compression: Minlz
 rocksdb.compression_options: window_bits=-14; level=32767; strategy=0; max_dict_bytes=0; zstd_max_train_bytes=0; enabled=0; 
 rocksdb.comparator: pebble.internal.testkeys
 rocksdb.data.size: 0